JPH0611593A - Inspection device for internal pump - Google Patents

Abstract

PURPOSE:To photograph and inspect simply and directly the depth in the casing of an internal pump. CONSTITUTION:The probe 10 of a fiberscope inserted in a casing 21 is put on a receiving seat 13. The receiving seat 13 is fixed on a cylindrical shaft 17. Outside of the shaft 17, a cylinder 14 sealed with an upper plug 15 and a lower plug 16 is provided. The lower plug 16 is fixed on a base flange 37 by way of a frame 26. A hydraulic hose 11 is connected to the upper plug 15 and the lower plug 16 and the cylinder 14 inside is pressurized to move a piston 18 up and down. The piston 18 is fixed outside of the cylindrical shaft 17. The fiber cable 55 of the probe 10 is penetrated out of a small flange. The fiber cable 55 is connected to a motor for rotational drive via a gear axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection device for an internal pump for observing deep inside the internal pump installed in an improved boiling water reactor.

[0002]

2. Description of the Related Art An improved boiling water reactor uses an internal pump as a reactor recirculation pump. The components of this pump are roughly classified into a casing of a pump body, a diffuser, a stretch tube, a propeller, and a shaft. And a water immersion motor.

The seal of the reactor water is the packing between the diffuser and the stub tube top surface, the secondary seal and the shaft circumference.
It is done in one place.

When the internal pump is disassembled and then reassembled, the diffuser and the stretch tube are put in the reactor pressure vessel and positioned, and then the end of the stretch tube is fastened to the casing with a tightening nut.

After tightening, the lock sleeve is inserted into the groove of the tightening nut as a detent. In addition, a secondary seal is provided alongside the end surface of the tightening nut. Water pressure is applied to this seal from a water pressure pipe to press the seal material around the shaft axis.

Whether or not these functions are fulfilled is directly related to whether or not the reactor water has entered the casing during the motor assembly after inserting the propeller and the shaft. Therefore, it is necessary to check the condition inside the casing once before inserting the propeller and the shaft.

What can be said regarding the repair of the internal pump is, for example, after the reassembly, it is necessary to continuously operate for several years except during the periodic inspection. Therefore, the damaged portion must be replaced with a new one, and the malfunctioning part can be used. It must be replaced as well.

In that sense as well, it is necessary to thoroughly inspect at the time of reassembling and to confirm even after mounting, while on the other hand, during reassembling work, it is necessary to be careful to prevent intrusion of reactor water.

Conventionally, there has been no particular disclosure of an inspection device for inspecting the inside of the casing of the internal pump, but as a conventionally known technique, for example, regarding a tightening nut, an automatic assembly by a special machine called a stretch tube handling tool is used. Has been done. As for the secondary seal, it is known that a so-called leak test, in which pressurized water is sealed before the secondary seal to check for leakage with the test shaft, is performed semi-automatically by a dedicated machine. .

As described above, it was considered impossible to search for the inside of the casing due to the darkness of the hand, and an automatic device was used. This automated work is more accurate than manual work.

[0011]

However, from the standpoint of confirmation before driving, it is not possible to rely only on the accuracy of the dedicated machine, and there is a problem in which it is necessary to confirm after installation with a human eye comprehensively. is there.

To cope with the above problem, it is desired to attach a video camera or the like having functions such as movement and rotation to a handling tool of a conventional internal pump, photograph the inside of the casing and inspect it. However, there is little room for adding complex functions to conventional handling tools.
Therefore, there is a demand for an inspection device that is easy to handle and that does not disturb the process during reassembly work.

The present invention has been made to solve the above problems, and it is an object of the present invention to provide an inspection device for an internal pump, which is capable of taking a picture directly and deeply inside a casing of an internal pump.

[0014]

DISCLOSURE OF THE INVENTION The present invention is directed to a fiberscope probe inserted into a casing of an internal pump, a vertical motion transmission mechanism for supporting the probe and imparting a vertical motion, and a rotary motion of the probe. A rotary motion transmitting mechanism for imparting motion, and a base flange for mounting and fixing the rotary motion transmitting mechanism and the vertical motion transmitting mechanism and detachably attached to the flange of the casing. .

[0015]

Operation: The probe of the fiberscope is inserted into the casing of the internal pump, and the probe is rotated or moved vertically and horizontally. Then, with the probe, the inside of the casing is projected on the monitor installed outside the casing for inspection.

The probe is rotated by rotating a gear shaft by a motor and rotating a rotary tube fixed to an internal gear body meshing with the coaxial pinion from side to side. As a result, the probe is rotated by rotating the cable tube that slides with the rotating tube.

When the probe is driven up and down, the piston is pressed to move the shaft up and down. The rotation tube and the cable tube are slid by engaging the slit of the rotation tube with the notch of the cable tube. The rotation of the rotating tube is transmitted to the cable tube and the probe via the notch.

The above inspection device is inserted into the casing by being fed by the guide screw of the lifting device. From the open end of the casing, through the inner wall of the casing, inspect the deep inside. When the flange of the inspection device is fitted to the flange of the casing, the inspection of the inside of the casing is completed, and then the probe is moved to inspect the inside of the secondary seal, the tightening nut, and the stretch tube.

When the probe rotates as described above, it is possible to inspect the entire inside of the portion to be inspected. As the probe moves up and down, you can extend your legs to the inside of the stretch tube for inspection. The field-of-view fiber of the fiberscope is imaged through a lens provided outside the casing and a camera, numbered by a video writer, and then displayed on a monitor screen by a video deck.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an internal pump inspection device according to the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing a state in which the inspection device of this embodiment is inserted into the casing of an internal pump. 2 shows a portion of the tightening nut and the secondary seal of FIG. 1, and FIG. 3 shows a partially enlarged view of the rotation mechanism portion of FIG.

Before explaining the inspection device, an outline of the upper structure of the internal pump will be described with reference to FIGS. 1 and 2. Reference numeral 1 is a shroud that is erected in the reactor pressure vessel 2 partially shown via a shroud support 3, and an internal pump is installed in a stub tube 4 erected between the shroud 1 and the reactor pressure vessel 2. The tip of the reduced diameter portion of the casing 21 is connected.

A diffuser 5 is arranged on the upper end surface of the stub tube 4. An opening is provided in the shroud support 3 and serves as a water inlet for reactor water to the inside of the shroud 1. The top surface of the stub tube 4 serves as a mounting surface for the diffuser 5. The packing 56 interposed between the stub tube 4 and the diffuser 5 prevents intrusion of reactor water.

The upper end of the stretch tube 7 inserted into the reduced diameter portion of the casing 21 engages with the lower end of the diffuser 5, and the lower end of the stretch tube 7 is tightened with a tightening nut 8. A lock sleeve 22 provided at the end of the stretch tube 7 serves as a detent for the tightening nut 8.

A secondary seal 9 provided below the tightening nut 8 seals the shaft circumference when the shaft of the internal pump is inserted. The tightening nut 8 is tightened to the casing 21 via the bearing surface of the lock sleeve 22. The water pressure pipe 23 is a pipe for pressurized water which is fed when the shaft is sealed.

In the lock sleeve 22, the thin cylindrical portion of the outer circumference formed from the seat surface is pressed and deformed at a plurality of places to tighten the nut 8.
It bites into and has a detent effect. The seating surface of the lock sleeve 22 below the thin-walled cylinder is fastened to the casing 21 in advance. A secondary seal 9 is attached to the casing 21 with a small gap in front of the tightening nut 8. A flexible sealing material is provided on the inner surface, and when pressurized, it bites around the internal pump shaft and seals.

Next, the inspection apparatus of this embodiment will be described with reference to FIG. 1 and the partially enlarged views of FIGS. 2 and 3. Reference numeral 10 indicates a fiberscope probe.
This will be described later with reference to FIG. A fiber cable 55 is connected to the probe 10, the end of the fiber cable 55 is led out of the casing 21, and the outside of the fiber cable 55 is protected by the cable tube 20.

The probe 10 is rotatably mounted on the receiving seat 13 via the snap ring 12. The receiving seat 13 is fixed to the hollow shaft 17 by welding or the like. A cylinder 14 is provided on the outside of the shaft 17 via an upper stopper 15 and a lower stopper 16.

The outside of the cable tube 20 is surrounded by a rotary tube 19, and the rotary tube 19 is connected to a mounting seat 57 in the frame 26 in which an internal gear is formed. The frame 26 is connected and fixed to the lower surface of the lower plug 16 and the upper surface of the base flange 37 by screws. The gear shaft 27 is screwed to the lower surface of the mounting seat 57 via a pressing plate 58.

The gear shaft 27 is a gear via a snap ring 28.
29 is installed. A fiber cable 55 is inserted into the gear shaft 27. The gear 29 meshes with the rotating shaft of the motor 31 via the pinion 30. The motor 31 is fixed to the base 36, and the base 36 is screwed to the base flange 37.

The lower side of the gear shaft 27 penetrates the base flange 37, and the thrust flange 32 and the thrust collar 33 surround the outer peripheral surface of the gear shaft 27 in the base flange 37.
The lower surface of the base flange 37 is surrounded by the screw plug 34. A small flange 35 is attached to the lower surface of the base flange 37.

A hydraulic hose 11 is connected to each of the upper stopper 15 and the lower stopper 16. A notch 40 is attached to the cable tube 20, the notch 40 is attached to the cable tube 20, and the rotating tube 19
Slide in the slit. When pressurized water is sent from below the piston 18 attached to the lower surface of the shaft 17 via the hydraulic hose 11, the shaft 17 moves via the piston 18 and the probe 10 moves up and down via the receiving seat 13. At that time, the cable tube 20 and the receiving seat 13 both move up and down. Then, the notch 40 slides while being engaged with the rotary tube 19.

The water pipe 24 communicates with the inside of the cylinder 14 through the upper plug 15, and the outside is connected to the hydraulic hose 11. Hydraulic hose 11
Although not shown in the figure, the terminal is connected to the water pressure pump and the drain tank by switching them at any time.

FIG. 3 shows an enlarged view of the vertical and rotational movement transmission mechanism of the probe 10. The vertical motion transmission mechanism of the probe 10 mainly comprises a cylinder 14, an upper plug 15, a lower plug 16, a shaft 17, a piston 18 and a hydraulic hose 11, and a rotary motion transmission mechanism mainly comprises a gear shaft 27, a gear 29, a pinion 30 and a motor 31. It consists of

In FIG. 3, the outside of the piston 18 integrated with the shaft 17 contacts the inside of the cylinder 14,
17 is closed by an end plug 25. Rotating tube penetrating this end plug 25
19 projects out of the cylinder 14 and is fixed to a mounting seat 57 in the frame 26 by welding or the like. An internal gear is formed outside the mounting seat 57.

Inside the rotary tube 19, a cable tube that is free to slide
20 also stands on the mounting seat 57 of the internal gear. FIG. 3 shows a state in which the probe 10 is set, and the cable tube 20 rises as the probe 10 rises when the shaft moves.

An idle pinion 30 that meshes with an internal gear formed on the outer surface of the mounting seat 57 is rotatably mounted across the frame 26, and a gear 29 mounted on the shaft end of the gear shaft 27 meshes with the pinion 30. .

In this way, when the internal gear of the mounting seat 57 rotates and the rotary tube 19 rotates, the gear 29 is locked by the key of the gear shaft 27 and the snap ring 28, but meshes with the pinion 30. . The pinion 30 is locked to the shaft end of the motor 31.

The base flange 37 also serves as a mounting seat for the motor 31. A pair of left and right casing bearings 38 are provided on the outside of the flange portion of the casing 21.
The shaft end of the screw rod is accommodated in 38. A pair of left and right nuts 39 provided on both sides of the base flange 37 can be screwed into a screw rod to move up and down.

FIG. 4 is a system diagram showing the fiberscope and its probe 10 in FIG. 1 and its imaging transmission system. The probe 10 is a prism 51 for the inspected part for observing the inspected part 50 in the casing of the internal pump.
And a field-of-view prism 54 for transmitting light.
The inspected part 50 is, for example, the inner deep part of the casing 21.

Light is irradiated onto the inspected part 50 from the inspected part prism 51 as shown by the arrow, and the system path from the prism 51 is connected to the light source fiber 49. On the other hand, the system path that receives the reflected light via the viewing prism 54 and sends it through the lens 53 is connected to the viewing fiber 52. These prisms 51, 54,
The probe 10 is a compact assembly of the lens 53 and the fibers 49, 52.

The probe 10 is fixed to the cable tube 20, and the rotation of the cable tube 20 causes the light source fiber 49 and the field of view fiber 52 to sequentially illuminate the surroundings and receive the reflected light. The arrows above and below the probe 10 are the cylinders shown in FIG.
The probe 10 moves up and down as the shaft 17 integrated with the piston 18 in 14 and the receiving seat 13 integrated with it move.

In this case, of course, the cable tube 20 also goes up and down. The fiber drum 55 takes in the fiber cable 55 and extends it to prevent damage. The light source 46 is a device that sends out light to the fiber cable 55.

The image passed through the lens 45 is captured by the camera 44, and the video typewriter 43 performs numbering if necessary. And monitor as playback recording on VCR 42
Broadcast on 41. Depending on the case, if a video printer is used together with the monitor 41, important points can be printed out.

When disassembling and reassembling the internal pump for periodic inspection and the like, the casing is filled with fresh water so that the reactor water does not enter the casing even if disassembled. When the maintenance is finished, for example, a dedicated underwater tool is hung by a service platform or the like on the furnace, and the diffuser 5 and the stretch tube 7 are seated on the stub tube 4 in a seated state.

The stretch tube 7 is inserted into the reduced diameter portion of the casing 21. After that, the hollow portion of the boss portion of the diffuser 5 is closed by using the plug 6, and heavy packing pressure is applied to the packing 56.

Once, clear water is drained from the inside of the casing 21, the not-shown closing flange of the casing 21 is opened, and a stretch tube handling device (not shown) is inserted into the casing by using the platform on the pedestal side and the lifting device, and the tightening nut 8 is tightened. Tighten and then lock sleeve 22 to prevent rotation.

Next, the secondary seal 9 is loaded, and the handling tool for the stretch tube 7 is removed from the casing. Next, the inspection device of the present invention is attached to the screw rod of the lifting device. The nuts on both sides of the base flange 37 are screwed onto the screw rod of the elevating device to raise. When the probe 10 starts to enter the casing 21, the inner wall is checked.

The motor 29 is driven to rotate the gear 29, and the pinion 30 at the end of the gear shaft 27 and the idle are driven to rotate the internal gear to move the notch of the cable pipe 20 from the slit of the integral rotary pipe 19. The cable tube (20) is turned through, and the probe (10) integrated with the cable tube (20) is turned. As the lifting device rises, the casing inner wall is inspected to check the image on the monitor 41.

The rising is further continued until the state shown in FIG. Next, pressure water is fed from below the piston 18 to raise the shaft 17, and the secondary seal and the tightening nut are inspected in this order, and the image is continuously displayed on the monitor 41. After that, the inner wall of the stretch tube 7 is continuously inspected.

When the inspection is completed, stop the motor 31 and turn the rotary tube.
Stop rotation of 19. Further, the water pressure hose 11 is reconnected on the pump side and pressured water is fed from above to bring the state of FIG.
After that, again using the lifting device, the base flange of the inspection device
37 may be pulled down and if necessary, lowered while re-inspecting the inside of the casing.

The probe 10 can be moved up and down and moved up and down freely, and is always rotatable. However, since the fiber cable passes through the center of the cable tube 20, there is no trouble such as twisting and the inspection work can be carried out smoothly.

Thus, after removing the inspection device, the opening end of the casing 21 is again sealed with a sealing flange (not shown), filled with fresh water, the plug 6 is pulled out, and a propeller and a shaft are attached instead.

The shaft is sealed around the shaft by a secondary seal, and the packing 56 is sealed by a tightening nut.
Next, drain the casing clean water and remove the sealing flange. Then, again by the elevating device, the rotor of the submerged motor 31 is fitted to fit the key of the shaft of the propeller that is suspended, and the casing 21 is fitted with the submerged motor flange (not shown).
Close and close the reassembly work.

[0054]

According to the present invention, the inner surface of the casing, the secondary seal, the tightening nut, the stretch tube, and the like can be continuously inspected at the time of mounting. With this inspection,
It is possible to eliminate the risk of water leakage during installation work of the propeller, shaft and submerged motor, and prepare for long-term operation after reassembly. In addition, rotation of the probe of the fiberscope in the dark place in the deep part of the special shape that the human view can not reach,
By moving, it is possible to send images to the monitor without exception.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a state in which an embodiment of an internal pump inspection device according to the present invention is inserted into a pump casing.

2 is a vertical cross-sectional view showing a partially enlarged view of a mounting state of a tightening nut and a secondary seal in FIG.

3 is a vertical cross-sectional view showing a partially enlarged rotary mechanism portion in FIG.

FIG. 4 is a system diagram showing a fiberscope in the fiber case in FIG. 1 and an imaging transmission system thereof.

[Explanation of symbols]

1 ... Shroud, 2 ... Reactor pressure vessel, 3 ... Shroud support, 4 ... Stub tube, 5 ... Diffuser, 6
… Plug, 7… Stretch tube, 8… Tightening nut, 9… Secondary seal, 10… Probe, 11… Hydraulic hose,
12 ... Snap ring, 13 ... Batch, 14 ... Cylinder, 15 ...
Upper stopper, 16 ... Lower stopper, 17 ... Shaft, 18 ... Piston, 19 ... Rotating pipe, 20 ... Cable pipe, 21 ... Casing, 22 ... Lock sleeve, 23 ... Water pressure pipe, 24 ... Water pipe, 25 ... End plug, 26 … Frame, 27… Gear shaft, 28… Snap ring, 29… Gear, 30…
Pinion, 31 ... Motor, 32 ... Thrust flange, 33 ... Thrust collar, 34 ... Screw plug, 35 ... Small flange, 36 ... Base,
37 ... Base flange, 38 ... Casing bearing, 39 ... Nut, 40 ... Notch, 41 ... Monitor, 42 ... VCR, 43 ...
Video typewriter, 44 ... Camera, 45 ... Lens, 46 ... Light source, 47 ... Fiberscope, 48 ... Fiber drum, 49 ...
Fiber for light source, 50 ... Inspected part, 51 ... Prism for inspected part, 52 ... View fiber, 53 ... Lens, 54 ... View prism, 55 ... Fiber cable, 56 ... Packing, 57 ... Mounting seat, 58 ... Presser plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Watanabe 4-7-7 Shiba, Minato-ku, Tokyo Aitel Technical Service Co., Ltd.

Claims (1)

[Claims] 1. A probe for a fiberscope inserted into a casing of an internal pump, a vertical motion transmission mechanism for supporting the probe and imparting a vertical motion, and a rotary motion transmission for imparting a rotary motion to the probe. An inspection device for an internal pump, comprising: a mechanism; and a base flange that mounts and fixes the rotary motion transmission mechanism and the vertical motion transmission mechanism and is detachably attached to a flange of the casing.